1. Field Of The Invention
The present invention relates generally to retractable awnings of the type adapted to be mounted on a substantially vertical surface and including a roll bar about which a canopy can be rolled and, more specifically, to a lock mechanism to selectively prevent rolling motion of the roll bar to thereby assist in retaining the awning in either its retracted or extended positions.
2. Description Of The Prior Art
Retractable awnings have been in use for many years with early uses being primarily as covers for windows, doors and the like. More recently, retractable awnings have been designed for use on mobile structures such as recreational vehicles, and mobile homes and, accordingly, out of necessity, the awnings have needed to include more sophisticated systems for retaining the awning in either its retracted or extended position.
As will be appreciated, when such an awning is mounted on a mobile vehicle, wind currents and other movement of the vehicle tend to unfurl the canopy portion of the awning or encourage the awning to be released from its retracted position and, accordingly, systems have been designed to retain the awning in the retracted position. Further, when the awning is in use, wind currents and the like also tend to move the awning and sometimes it is difficult to maintain the awning in an extended position and for this reason the awnings have been carefuly designed so as to be braced and otherwise securely retained in the extended position.
Most modern retractable awnings include a roll bar which is mounted on the end of a pair of support arms so as to be moved from a retracted position adjacent to a substantially vertical surface on which the awning is mounted to an extended position displaced therefrom and wherein the canopy is adapted to be wrapped around the roll bar as it is moved from the extended to the retracted position. As will be appreciated, when moving awnings, and particularly large retractable awnings, it is desirable to control movement of the roll bar by permitting movement of the roll bar in only one direction at a time. In other words, when operating the awning, it is most easily maneuvered when the roll bar is permitted to roll in one direction only and is locked or otherwise prevented from moving in the opposite direction. Of course, these directions need to be reversible so that the awning is easily moved between its retracted and extended positions.
Many such systems have been designed for controlling the rolling movement of the roll bar during operation of the awning with one system being disclosed in U.S. Pat. No. 3,870,096 assigned to Carter Mfg., Inc. In this system, an eccentric lock is mounted in the end of the roll bar which permits, in one position, rolling movement of the roll bar in a first direction while preventing movement in the opposite direction and in a second position, permits rolling movement in the opposite direction while preventing movement in the first direction. While this system has proven effective in controlling movement of the roll bar, it has been found that it is difficult to operate, particularly from a remote location due to the fact that the eccentric lock needs to be rotated almost 360.degree. between its two alternative locking positions. While such movement is not difficult when directly operating the lock, the lock is frequently out of the reach of the operator and, accordingly, is typically actuated from a location which is removed from the lock and, accordingly, complicated mechanical systems are required to accomplish the 360.degree. rotation. It is to overcome such shortcomings in the prior art that the present invention has been developed.